When you
receive this event, the structure members are set as
follows.

The type member
is set to the event type constant name that uniquely
identifies it. For example, when the X server reports a
GraphicsExpose event to a client application, it
sends an XGraphicsExposeEvent structure with the type
member set to GraphicsExpose. The display member is
set to a pointer to the display the event was read on. The
send_event member is set to True if the event came
from a SendEvent protocol request. The serial member
is set from the serial number reported in the protocol but
expanded from the 16-bit least-significant bits to a full
32-bit value. The window member is set to the window that is
most useful to toolkit dispatchers.

The requestor
member is set to the window associated with the requestor of
the selection. The selection member is set to the atom that
indicates the selection. For example, PRIMARY is used for
the primary selection. The target member is set to the atom
that indicates the converted type. For example, PIXMAP is
used for a pixmap. The property member is set to the atom
that indicates which property the result was stored on. If
the conversion failed, the property member is set to
None. The time member is set to the time the
conversion took place and can be a timestamp or
CurrentTime.